#WinterWednesday: Frost Heave and Foundation Damage - Carolina Foundation

#WinterWednesday: Frost Heave and Foundation Damage

frost heave foundation damage

The new year welcomed the South with a chilly blow of record low temperatures and winter storm conditions with rare snow falls happening along the east coast in Charleston, SC, Savannah, GA and Tallahassee, FL, where residents saw snow for the first time in nearly 30 years. Meteorologists called the uncharacteristic weather patterns a “bomb cyclone” due to the fast atmospheric pressure drop. With freezing temperatures brings the potential detriment of frost heave. Frost heave occurs when water from unfrozen soil is drawn to a freezing zone and attaches to layers of ice which forces soil particles apart causing the soil surface to heave and displacing structures that rest upon it.

Conventional foundation design aims to prevent frost damage by placing footings beyond the depth of the expected frost penetration, however, if during excavation the area is backfilled with frost-susceptible soil it may lead to damage from adfreezing. Adfreezing occurs when two objects are bonded together by ice formed between them. Frost heave and foundation settlement can be difficult to distinguish from one another since both types of moving cause similar cracking.

Evidence of frost heave:

  • Broken edges of cracked sections of concrete
  • History of poor site drainage
  • Absent evidence of backfill at a poured concrete structure, such as a garage slab with a crack across the width of the site near the entry.

Winterizing steps to avoid foundation problems:

  • Backfilling footings with gravel to aid in drainage
  • Using clean sand and gravel under floor slabs for insulation to reduce frost penetration
  • Replacing fine-grain, frost-susceptible soil with coarse-grained material not susceptible to heaving help prevent foundation damage from frost heave.

While the Carolinas typically experience mild winters, this should not instill a false sense of security in homeowners and business owners that they are spared from winter damage. Protect your biggest investment from the winter weather by calling Carolina Foundation Solutions to schedule a FREE consultation for visit bit.ly/CFSConsult.


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